Best Time to Visit Koh Samui for Different Goals

Goals

• Goal: Best all-round weather · Answer: February and March (dry, sunny, calm sea). January and April are close behind; April is hotter.
• Goal: Best value with still-good weather · Answer: May, June and July - mostly fine weather, lower prices, fewer crowds.
• Goal: European summer holidays (July-August) · Answer: Koh Samui is usually a better choice than Phuket at this time, because the Gulf coast is drier mid-year.
• Goal: Christmas and New Year · Answer: Good weather usually returns by mid-December, but it is the busiest and most expensive period; book early.
• Goal: Snorkelling and boat trips (Ang Thong, Koh Tao) · Answer: January to June, when seas are calmest. Ang Thong Marine Park usually closes from 1 November (2026 reopening date not yet confirmed)^[1].
• Goal: Avoid · Answer: October and November if weather matters - this is the wettest, roughest period. If you must travel then, Phuket (Andaman coast) is usually drier.

1. [1] Tourism Authority of Thailand — national park seasonal closures · checked 2026-11-10